Forensic analysis frequently requires that evidence be captured and preserved until it can be analyzed in a laboratory setting or presented to a court of law. Such evidence may include biological substances, such as blood, saliva, urine or semen, which may need to be identified and subjected to chemical and/or DNA analysis for identification or for association with a particular individual.
The use of fibrous swabs for collecting specimen samples has become ubiquitous in the forensic arts. Such swabs, which typically comprise cotton, not only absorb liquids (and solids suspended in liquids), but also effectively capture dry particulate substances.
Prior to use, the swabs are typically kept in closed, sterile containers known as swab canisters to avoid exposure to environmental contaminants. Similarly, after a swab has been used to collect a specimen, it is typically placed in a sterile bag or container to avoid contamination during subsequent handing. In order to establish a chain of custody of the sample, it is common to mark the bag or container with appropriate information. Such information may include, for example, the time, date and location at which the sample was collected, the identity of the party who collected the sample, and a unique sample identifier. The bag or container containing the swab may also be provided with a desiccant to remove any excess moisture present in the sample, since such moisture can promote the growth of bacteria in the sample. Left unchecked, such bacterial growth can lead to sample degradation, which can complicate forensic analysis and potentially render the sample useless.
Sample swabs may also become contaminated during use as a result of careless handling. For example, an investigator at a crime scene may put a swab down after it has been used to collect a sample, but before the swab has been placed in a sterile bag or container. This may occur, for example, while the investigator is opening a bag or container into which the swab will be placed, or is allowing the swab to dry. During this time, the swab may become contaminated as a result of coming into contact with one or more surfaces.
Various devices and methodologies have been proposed in the art to reduce or minimize the contamination of sample swabs during use. For example, U.S. Pat. No. 8,940,547 (Sangha) and U.S. Pat. No. 9,052,254 (Sangha), FIGS. 1-2 of which have been reproduced as FIGS. 1-2 herein, disclose a swab-based evidence collecting apparatus 10 which features a shaft 16 having a swab 14 mounted on a first end thereof. A second end of the shaft 16 is connected to a closure 18. The closure 18 comprises a central member 20 having a stopper 22a, 22b which extends from each of the opposing sides of the central member.
The specimen collector 12 further includes a rigid break-off tube 24 which is mounted coaxially on the shaft 16. A first end of the tube 24 is connected to the closure 18. A second end of the tube 24 is configured to terminate at a selected location along the shaft 16 at which the shaft may be broken in order to achieve separation of the swab 14 from the remainder of the apparatus 10.
Closure 18 comprises a central member 20 and is equipped with a stopper 22a, 22b extending from each of the two opposing sides of the central member 20. The apparatus 10 is depicted with the stopper 22a having a shaft 16 and tube 24 connected thereto, and with the stopper 22b inserted into the neck 26 of the housing 28 of the apparatus 10.
FIG. 1 depicts the apparatus 10 in an open position in which the specimen collector 12 has been removed from housing 28, and in which the closure 18 has been reversed and inserted into opening 30 (see FIG. 2) of the neck 26 of housing 28 from which the specimen collector 12 was just removed. This reversal and insertion allows the housing 28 to act as a handle for manipulating the swab 14 of specimen collector 12 during the collection of a specimen. The relatively large, flat surface of desiccant chamber 32 fits securely into the palm of the hand and prevents the apparatus 10 from moving when it is placed on a surface. When positioned on a surface, the edge of the closure 18 extends laterally beyond the swab 14 and keeps the swab 14 separated from any contact with adjacent contaminating surfaces. In the closed position, the specimen collector 12 is inserted into the housing 28 and the stopper 22a of closure 18 is inserted into the opening 30 (see FIG. 2).
As seen in FIG. 2, the housing 28 includes a desiccant chamber 32 which is connected to the neck 26 of the housing 28. The desiccant chamber 32 is equipped with a resealable cover 34 that forms the bottom of the housing 28. The cover 34 may be generally flat to allow the apparatus 10 to stand on a surface. The cover 34 may be removably connected to desiccant chamber 32, or it may be permanently sealed to close chamber 32.
As seen in FIG. 2, the desiccant chamber 32 is equipped with fixed retainers 38 that hold desiccant packets 36 in position therein. When the swab 14 is positioned within the housing 28, it is situated between the retainers 38 in a swab isolation area 41, with the retainers 38, 40 holding the desiccant packets 20 away from the swab 14.